DPOAE recovery from loud sound exposure

In this investigation normal hearing subjects are exposed to sound that causes a temporary threshold shift (TTS), see project "Temporary Threshold Shifts Due to Short Tonal Over-Exposure". Distortion product otoacoustic emissions (DPOAEs) are measured in certain time intervals after the exposure. From these measurements frequency and time specific changes in the OAE recovery are observed. The purpose of this study is to find appropriate measurement parameters for measuring DPOAE changes and to determine the relevant time intervals and frequency range of the changes. The measurements are compared to TTS measurements under the same conditions. Similarities between the temporary shift of DPOAE and TTS have been found in the affected frequency range and the time course of recovery. The amount of TTS is higher in the early recovery time (1-4 minutes post- exposure), but similar to the DPOAE shift (even in absolute terms) at later recovery times (5-20 minutes post-exposure). Supported by PhD scholarship by the Oticon Foundation and STVF/FTP.